Lastly there sprang up in the aesthetic literature of this period the artistic treatment of subjects of professional science in the form of the stylistic dialogue, which had been very extensively in use among the Greeks and had been already employed also in isolated cases among the Romans[37]. Cicero especially made various attempts at presenting rhetorical and philosophical subjects in this form and making the professional manual a suitable book for reading. His chief writings are the De Oratore (written in 699), to which the history of Roman eloquence (the dialogue Brutus, written in 708) and other minor rhetorical essays were added by way of supplement; and the treatise De Republica (written in 700), with which the treatise De Legibus (written in 702?) after the model of Plato is brought into connection. They are no great works of art, but undoubtedly they are the works in which the excellences of the author are most, and his defects least, conspicuous. The rhetorical writings are far from coming up to the didactic chasteness of form and precision of thought of the Rhetoric dedicated to Herennius, but they contain instead a store of practical forensic experience and forensic anecdotes of all sorts easily and tastefully set forth, and in fact solve the problem of combining didactic instruction with amusement. The treatise De Republica carries out, in a singular mongrel compound of history and philosophy, the leading idea that the existing constitution of Rome is substantially the ideal state-organization sought for by the philosophers; an idea indeed just as unphilosophical as unhistorical, and besides not even peculiar to the author, but which, as may readily be conceived, became and remained popular.

The scientific groundwork of these rhetorical and political writings of Cicero belongs of course entirely to the Greeks, and many of the details also, such as the grand concluding effect in the treatise De Republica the Dream of Scipio, are directly borrowed from them; yet they possess comparative originality, inasmuch as the elaboration shows throughout Roman local colouring, and the proud consciousness of political life, which the Roman was certainly entitled to feel as compared with the Greeks, makes the author even confront his Greek instructors with a certain independence. The form of Cicero's dialogue is doubtless neither the genuine interrogative dialectics of the best Greek artificial dialogue nor the genuine conversational tone of Diderot or Lessing; but the great groups of advocates gathering around Crassus and Antonius and of the older and younger statesmen of the Scipionic circle furnish a lively and effective framework, fitting channels for the introduction of historical references and anecdotes, and convenient resting-points for the scientific discussion. The style is quite as elaborate and polished as in the best-written orations, and so far more pleasing than these, since the author does not often in this field make a vain attempt at pathos. While these rhetorical and political writings of Cicero with a philosophic colouring are not devoid of merit, the compiler on the other hand completely failed, when in the involuntary leisure of the last years of his life (709-710) he applied himself to philosophy proper, and with equal peevishness and precipitation composed in a couple of months a philosophical library. The receipt was very simple. In rude imitation of the popular writings of Aristotle, in which the form of dialogue was employed chiefly for the setting forth and criticising of the different older systems, Cicero stitched together the Epicurean, Stoic, and Syncretist writings handling the same problem, as they came or were given to his hand, into a so-called dialogue. And all that he did on his own part was, to supply an introduction prefixed to the new book from the ample collection of prefaces for future works which he had beside him; to impart a certain popular character, inasmuch as he interwove Roman examples and references, and sometimes digressed to subjects irrelevant but more familiar to the writer and the reader, such as the treatment of the deportment of the orator in the De Officiis; and to exhibit that sort of bungling, which a man of letters, who has not attained to philosophic thinking or even to philosophic knowledge and who works rapidly and boldly, shows in the reproduction of dialectic trains of thought.

In this way no doubt a multitude of thick tomes might very quickly come into existence - "They are copies", wrote the author himself to a friend who wondered at his fertility; "they give me little trouble, for I supply only the words and these I have in abundance". Against this nothing further could be said; but any one who seeks classical productions in works so written can only be advised to study in literary matters a becoming silence.

Of the sciences only a single one manifested vigorous life, that of Latin philology. The scheme of linguistic and antiquarian research within the domain of the Latin race, planned by Silo, was carried out especially by his disciple Varro on the grandest scale. There appeared comprehensive elaborations of the whole stores of the language, more especially the extensive grammatical commentaries of Figulus and the great work of Varro De Lingua Latina; monographs on grammar and the history of the language, such as Varro's writings on the usage of the Latin language, on synonyms, on the age of the letters, on the origin of the Latin tongue; scholia on the older literature, especially on Plautus; works of literary history, biographies of poets, investigations into the earlier drama, into the scenic division of the comedies of Plautus, and into their genuineness. Latin archaeology, which embraced the whole older history and the ritual law apart from practical jurisprudence, was comprehended in Varro's "Antiquities of Things Human and Divine", which was and for all times remained the fundamental treatise on the subject (published between 687 and 709). The first portion, "Of Things Human" described the primeval age of Rome, the divisions of city and country, the sciences of the years, months, and days, lastly, the public transactions at home and in war; in the second half, "Of Things Divine", the state-theology, the nature and significance of the colleges of experts, of the holy places, of the religious festivals, of sacrificial and votive gifts, and lastly of the gods themselves were summarily unfolded. Moreover, besides a number of monographs - e. g. on the descent of the Roman people, on the Roman gentes descended from Troy, on the tribes - there was added, as a larger and more independent supplement, the treatise "Of the Life of the Roman People" - a remarkable attempt at a history of Roman manners, which sketched a picture of the state of domestic life, finance, and culture in the regal, the early republican, the Hannibalic, and the most recent period. These labours of Varro were based on an empiric knowledge of the Roman world and its adjacent Hellenic domain more various and greater in its kind than any other Roman either before or after him possessed - a knowledge to which living observation and the study of literature alike contributed.

The eulogy of his contemporaries was well deserved, that Varro had enabled his countrymen - strangers in their own world - to know their position in their native land, and had taught the Romans who and where they were. But criticism and system will be sought for in vain. His Greek information seems to have come from somewhat confused sources, and there are traces that even in the Roman field the writer was not free from the influence of the historical romance of his time. The matter is doubtless inserted in a convenient and symmetrical framework, but not classified or treated methodically; and with all his efforts to bring tradition and personal observation into harmony, the scientific labours of Varro are not to be acquitted of a certain implicit faith in tradition or of an unpractical scholasticism[38]. The connection with Greek philology consists in the imitation of its defects more than of its excellences; for instance, the basing of etymologies on mere similarity of sound both in Varro himself and in the other philologues of this epoch runs into pure guesswork and often into downright absurdity[39]. In its empiric confidence and copiousness as well as in its empiric inadequacy and want of method the Varronian vividly reminds us of the English national philology, and just like the latter, finds its centre in the study of the older drama. We have already observed that the monarchical literature developed the rules of language in contradistinction to this linguistic empiricism[40]. It is in a high degree significant that there stands at the head of the modern grammarians no less a man than Caesar himself, who in his treatise on Analogy (given forth between 696 and 704) first undertook to bring free language under the power of law.